Room with damp in corner

IreneMot

Hello all, 

I am looking for some advice. We have a semi detached house that was built in the 1950s. It has cavity wall but not insulated because we always heard more good than bad so been a but unsure. The temps are always around 17c to 23 depending on time of day, heating, room, etc. The back windows have been replaced but the front windows are still wooden frames but double glazed.  
There is a small boxed room that has some sort of damp problem in the corner, see photo (Nothing has been stored in that corner). There is a big through wall ventilation that is blocked with tissue and has been for a good number of years because of a wasp nest that needs to be removed some how (the vent is fixed to the wall). I have got a Hygrometer in this room has been sitting at around 62% to 70% and from what I read those a perfect conditions for mold to grow.
Does anyone have any advice? I am planning on freeing that vent what should help matter. 

The lines are part of the wallpaper


  

neilmcl

Yes, get that vent cleared. I assume that the area is an external wall, can wee some pictures from the outside? Looks like condensation to me rather than damp due to poor ventilation.

IreneMot

neilmcl said:

Yes, get that vent cleared. I assume that the area is an external wall, can wee some pictures from the outside? Looks like condensation to me rather than damp due to poor ventilation.

Yes that is the external wall (front corner of the house). I will get some photos tomorrow and post, Not to sure how much it will help becuase the house was full rendered (not over the vents) way before I moved in. 

FreeBear

The humidity in most of the rooms here has been between 50% and 70% (hovering around 60%). Your readings are not excessive in comparison.

Personally, I dislike through wall vents (extractor fans in kitchens/bathrooms serve a purpose). They let valuable warm air out and are a source of nasty cold draughts - If ventilation is needed, fit a mechanical heat recovery system and stop wasting energy.. Is this damp patch under the air vent ?

Mutton_Geoff

Is that room heated? If it's cold, the moisture will tend to condense inside.

IreneMot

That is good to know about the humidity. I personal dont like there vent but if they fix the problem at the moment that I don't mind till I can sort something else house.

IreneMot

Mutton_Geoff said:

Is that room heated? If it's cold, the moisture will tend to condense inside.

The room is heat and the heating come on at 4 in the afternoon

IreneMot

@FreeBear
Forgot the say that the damp is in the corner of the house 

fenwick458

i'm not sure if unblocking the vent will help or not??

neilmcl

IreneMot said:

neilmcl said:

Yes, get that vent cleared. I assume that the area is an external wall, can wee some pictures from the outside? Looks like condensation to me rather than damp due to poor ventilation.

Yes that is the external wall (front corner of the house). I will get some photos tomorrow and post, Not to sure how much it will help becuase the house was full rendered (not over the vents) way before I moved in. 

Is there a downpipe from your guttering in that corner?

I still think it's most likely condensation and a bit of mould from a cold corner of the house.

IreneMot

@neilmcl
yes there is one on that corner but never noticed anything wrong and the gutters was cleared and the birds clean the to. 
yes I am in the same thinking from what I have read but unsure. Any recommendation for improvement apart from the vent?
thanks for the help by the way